Effect of cardiac hybrid ¹5O-water PET/CT imaging on downstream referral for invasive coronary angiography and revascularization rate.

AIMS: This study evaluates the impact of hybrid imaging on referral for invasive coronary angiography (ICA) and revascularization rates. METHODS AND RESULTS: A total of 375 patients underwent hybrid (15)O-water positron emission tomography (PET)/computed tomography (CT)-based coronary angiography (CTCA) imaging for the evaluation of coronary artery disease (CAD). Downstream treatment strategy within a 60-day period after hybrid PET/CTCA imaging for ICA referral and revascularization was assessed. CTCA examinations were classified as showing no (obstructive) CAD, equivocal (borderline test result), or obstructive CAD, while the PET perfusion images were classified into normal or abnormal. On the basis of CTCA imaging, 182 (49%) patients displayed no (obstructive) CAD. Only 10 (5%) patients who showed no (obstructive) CAD on CTCA were referred for ICA, which were all negative. An equivocal CT study was observed in 80 (21%) patients, among whom 56 (70%) showed normal myocardial perfusion imaging (MPI), resulting in referral rates for ICA of 18% for normal MPI and 71% for abnormal MPI, respectively. No revascularizations were performed in the presence of normal MPI, while 59% of those with abnormal MPI were revascularized. CTCA indentified obstructive CAD in 113 (30%) patients accompanied in 59 (52%) patients with abnormal MPI. Referral rate for ICA was 57% for normal MPI and 88% for those with abnormal MPI, resulting in revascularization rates of 26% and 72%, respectively. CONCLUSION: Hybrid (15)O-water PET/CTCA imaging impacts clinical decision-making with regard to referral for ICA and revascularization procedures. Particularly, in the presence of an equivocal or abnormal CTCA, MPI could guide in the decision to refer for ICA and revascularization.